Cotton is much softer and pleasanter to the skin than wool, is cooler in hot weather, is much cheaper, and is very easily washed without losing either its shape or its porousness. It can be so woven as to be almost as porous as wool, and to retain that porousness even when saturated with perspiration. It does not soak up and retain the oils and odors of perspiration in the way that wool does; and on the whole, for under wear, and for general wear at the warm seasons of the year, it is not only more comfortable, but far more healthful, than wool. Persons of fair health and reasonably vigorous outdoor habits, whose skins are well bathed and ventilated, can wear properly woven cotton or linen undergarments the whole year round with perfect safety. [Illustration: A COMFORTABLE DRESS FOR OUTDOOR STUDY IN COLD WEATHER The thick bags pulled up to the shoulders keep the body surrounded by a layer of warm air.] Linen and silk both make admirable and healthful under wear, if woven with a properly porous mesh. Linen has the advantage of remaining more porous than cotton, when moist with perspiration. But for healthy people they have no advantages over cotton that are not offset by their higher prices. BATHS AND BATHING Bathing as a Means of Cleanliness. It has been said that one of the reasons why man lost his hairy coat was that he might be able to wash himself better and keep cleaner. However this may be, he has to wash a great deal oftener than other animals, most of whom get along very well with currying, licking, and other forms of dry washes, and an occasional swim in a river or lake. You can readily see how necessary for us washing is, when you remember the quarts of watery perspiration, which are poured out upon our skins every day, and the oily and other waste matters, some of them poisons, which the perspiration leaves upon our skins. Especially is some means of washing necessary when the free evaporation of perspiration and the free breathing of the skin has been interfered with by clothing which is water-tight or too thick.